Core B Project Summary Core B will work with each of the four projects to provide relevant immunoassays in mice and in humans: Project 1 with Dr Hedrick will use mouse models to test the impact of new monocyte subsets that regulate T and B cell responses in the artery wall, on atherogenesis and innate immunity. The Core will be able to measure IgG and IgM autoantibodies to oxidation-specific epitopes (OSE) and ApoB-immune complexes, as well as total IgG and IgM plasma levels to assess the impact of these monocyte subsets and interaction with lymphocytes on these measurements. These can then be analyzed according to B1 and B2 cell function from Dr. McNamara's projects and to also correlate with monocyte cytokine release from Dr. Ley's experiments. Project 2 with Dr. Miller will use the Core to measure oxidized cholesteryl esters on individual lipoproteins, an assay that has been co-developed by our laboratory with Dr. Miller and for which preliminary clinical data is provided in his section. Clinical assays that we have established, such as OxPL-apoB, Lp(a), and IgG and IgM autoantibodies and ApoB-immune complexes will also be measured. These measures can then be related to both the presence and extent of coronary artery calcium (CAC), as well as the progression of CAC and the relationship with cardiovascular events. Furthermore, they can be correlated with AIBP levels and HDL parameters from the various experiments. Project 3 with Dr McNamara will evaluate the mechanism that regulates their ability to produce atheroprotective moieties such as IgM to OSE. This project is expected to generate significant data in B1 biology in mouse models, all of which will be highly relevant to measuring IgG and IgM autoantibody titers. We also have the ability to measure the presence of the atheroprotective antibody E06 in such mice as we have access to an anti-idiotype antibody to E06, AB1-2. Finally, measuring total levels of IgG and IgM antibodies is an important aspect in interpreting experimental studies, which will also be measured. Such assays are currently available and have been previously described and published in collaborative work with Dr. McNamara Project 4 with Dr. Ley will define the size and nature of the ApoB-specific CD4 T cell in mice. The mouse apoB-immune complex assays capture murine apoB using murine monoclonal antibody antibody LF3 and then assess the presence of a bound antibody to the apoB. These assays will be highly relevant to this work in interpreting whether immune complexes containing murine apoB are generated in these mice. Furthermore, we can measure murine total apoB levels with these assays as a control measure.